Dating back to when Fairy Tail was originally acquired as a simulcast, the contract stipulated two unique conditions:

1. The episodes are only available for 30 days (this is what you are referring to).
2. The episodes are only available to premium members

While there are some episodes of shows that are available only to premium members, FT is the only simulcast that has this limitation for all regions.

I don't know of a single other anime, however, that has ever had the 30 day limitation Fairy Tail does. In fact, with one exception*, I don't know of any simulcast that hasn't at least been available for the duration of the broadcast plus at least a 30 day period thereafter.

I doubt CR would agree to such terms today to acquire a simulcast, but Fairy Tail was acquired only 10 months after CR went fully legit, and they needed all the simulcasts they could get. (Fall 2009 was only 16 simulcasts total, including continuing ones).

*That one exception? I'll spoiler it for those that want to see if they can remember it first.

Spoiler Alert! Click to show or hide

Strike Witches

This aired in summer 2008, half a year before CR would go fully legit. CR worked out a deal with Gonzo to simulcast the series, and I believe this was their first simulcast. Each episode was available for a short window. I can't recall exactly how long it was, but I believe it was somewhere in the neighborhood of 24-48 hours.

The one redeeming feature is that you could purchase each episode for download. This feature would be available on some later shows, although it didn't prove popular enough to retain.